Draft stabilizer



Patented July 5, 1938 PATENT OFFICE DRAFT STABILIZER Edward A. Field andEdward A. Field, Jr.,

' Chicago, Ill.

, Application July 26, 1935, Serial No. 33,242

Claims. (Cl. 236-45) Our present improvements are especially designed byus for embodiment in the draft stabilizer of Letters Patent No.1,855,228, issued to us April 26, 1932, and No. 1,873,567 issued to usAugust 23, 1932, and we have illustrated them as so embodied.

The main object of the invention is to provide a draft stabilizer welladapted for use in large power plants which is highly effective and notlikely to become clogged or rendered inaccurate by accumulations of dustor ash on the control gate or other parts.

A further object is to provide a stabilizer apparatus having theseadvantages which is very simple and economical in its parts.

Objects relating to details and economies of our invention will appearfrom the description to follow. The invention-is defined and pointed outin the claims.

A structure which is a preferred embodiment of our invention isillustrated in the accompanying drawing, in which:

Fig. 1 is a view of a draft stabilizer embodying our invention, thestabilizer housing and breeching with which it is associated being shownin vertical transverse section.

Fig. 2 is a fragmentary front perspective view with the gate and itscounterbalance omitted.

In the accompanying drawing, I represents the breeching of a power plantor heating system, the direction of flow therein being indicated by thearrow 2. The breeching has an opening 3 in one side wall thereof.

The stabilizer housing 4 is mounted on the side of the breeching as bymeans of the clamps 5, this housing being provided with an inlet opening6 and an outlet opening 1 registering with the opening 3 in thebreeching wall.

The stabilizer gate or damper 8 is provided with a pivot member 9rockingly or pivotally supported on the ledge-like member H1 at thebottom of the inlet opening, this being in the structure illustrated apart of an angle iron frame surrounding the opening. The gate is thussupported to swing inwardly in opening and its upper end issubstantially spaced from the top of the stabilizer housing.

The gate is provided with a downwardly projecting arm I i on which ismounted a supporting frame l2 for the adjustable weight indicated at 13.This weight is shifted along the supporting frame by means of the screwl4 driven from the motor l5. The automatic control mechanism for themotor is preferably that shown in our said 1 Patent No. 1,855,228 andis, therefore, not further illustrated and described herein.

The counterbalance is so arranged in relation to the gate that thedegree of opening of the gate varies substantially in accordance withthe variation of draft therefor, thus maintaining a substantiallyconstant draft in the firebox. The "relation of the counterweight andgate is substantially that described and claimed in our Patent No.1,783,418, issued December 2, 1930.

At the bottom of the outlet opening of the stabilizer housing, weprovide a shelf I6 disposed parallel to the top of the housing andbetween this shelf and the top of the housing we dispose a plurality oflouvers ll, these louvers being inclined in thedirection of flow of theflow within the breeching. In the embodiment illustrated, there is aspace 3 of greater width than the spaces between the louvers, this space18 being at the rear end of the opening relative to the direction offlow within the breeching. There is no necessity for louvers at thispoint because of the fact that there is always an inward flow of air atthis location. In a housing unprovided with louvers, the smoke will eddyinto the housing at the side nearest the boiler or furnace, but as longas the gate of the control housing is open even a slight amount, the airpassing the gate tends to crowd over to the side of the housing farthestfrom the boiler; i. e., it tends to pass through the space 18; and thisflow of air will prevent the entrance of smoke at that point. The louverblades are provided to prevent entrance of smoke throughout the rest ofthe area of the opening and are very effective, especially when theamount of air entering the housing through the gate is small.

This particular arrangement of louvers with the wider space describedresults in a very efficient operation, the deposit of soot or cinders orash within the housing and on the gate being very effectively prevented.

We have illustrated and described our improvements in a highly practicalembodiment. We have not attempted to illustrate or describe otherembodiments or adaptations as we believe this disclosure will enablethose skilled in the art to embody or adapt our improvements as may bedesired.

Having thus described our invention, What we claim as new and desire tosecure by Letters Patent, is:

1. In a draft stabilizer, the combination with a breeching having a sideopening therein, of a stabilizer housing having an inlet opening in itsfront wall and an outlet opening in its rear wall registering with saidopening in said breeching,

there being a shelf projecting into the housing at the bottom of theoutlet opening, a plurality of vertically disposed spaced louversdisposed within the stabilizer housing between said shelf 'and'the topof the housing, the louvers being inclined in the direction of flowwithin the breeching, there being a space at the rear end of the openingrelative to the flow within the breeching of greater width than thespaces between the louvers, and a counterbalanced gate for said inletopening pivoted at its lower end to swing inwardly in opening, the upperend of the. gate being substantially below the top of the housing andthe upper ends of the louvers.

2. In a draft stabilizer, the combination with a breeching having a sideopening therein, of a stabilizer housing having an inlet opening in itsfront wall and an outlet opening in its rear wall registering with saidopening in said breech ing, there being a shelf projecting into thehousing at the bottom of the outlet opening, a plurality of verticallydisposed spaced louvers disposed within the stabilizer housing betweensaid shelf and the top of the housing, the louvers being inclined in thedirection of flow within the breeching, and a counterbalanced gate forsaid inlet opening pivoted at its lower end to swin inwardly in opening,the upper end of the gate being substantially below the top of thehousing and the upper ends of the louvers.

3. In a draft stabilizer, the combination with a breeching having a sideopening therein, of a stasaid outlet opening disposed within thestabilizer housing, the louvers being inclined in the direction of flowwithin the breeching, there being a space at the rear end of the openingrelative to the flow within the breeching of greater width than thespaces between the louvers, and a counterbalanced gate for said inletopening pivoted at its lower end to swing inwardly in opening.

4. In a draft stabilizer, the combination with a horizontally disposedbreeching having a side opening therein, of a stabilizer housing havingan inlet opening in its front wall and an outlet opening in its rearwall registering with said opening in said breeching, a plurality ofvertically disposed louvers Within said housing with their edgessubstantially flush with the breeching opening, the louvers beinginclined toward the breeching and in the direction of flow within thebreeching, and a counterbalanced gate for said inlet opening pivoted atits lower end to swing inwardly in opening. 7

5. In a draft stabilizer, the combination with a breeching having a sideopening therein, of a stabilizer housing having an inlet opening in itsfront wall provided with a draft responsive inlet gate and an outletopening in its rear wall registering with said breeching opening, and aplurality of substantially parallel louvers within said housing withtheir rear edges closely adjacent to the breeching opening, the louversbeing inclined toward the breeching and in the direction of flow withinthe breeching.

EDWARD A. FIELD. EDWARD A. FIELD, JR.

